Sheet transfer mechanism



NGV- 18, 1952 H. E. PEYREBRUNE SHEET TRANSFER MECHANISM 8 Sheets-Sheet l Filed Aug. 3, 1948 NOV-'18, 1952 H. E. PEYREBRUNE:

SHEET TRANSFER MECHANISM 8 sheets-sheet 2 Filed Aug. 5, 1948 e m 4 R mw Ne 1P E H. Am M H v. B

H. E. PEYREBRUNE SHEET TRANSFER MECHANISM Nov. 18, 1952 Filed Aug. I5, 1948 Nov. 18, 1952 H. E. PEYREBRUNE SHEET TRANSFER MECHANISM Filed Aug.y 5, 1948 8 Sheets-Sheet 4 IN V EN TOR. Henri E. Peyrebrune Nov. 18, 1952 H. E. PEYREBRUNE SHEET TRANSFER MEcHANIsM 8 Sheets-Sheet 5 Filed Aug. 3, 1948 Nov. 18, 1952 H. E. PEYREBRUNE 2,618,479 Y SHEET TRANSFER MECHANISM 8 Sheets-Sheet 6 Filed Aug. s, 4948 4 INVENTOR. Hen/ff E. Peg/e brune NOV 18; 1952 H. E. PEYREBRUNE 2,618,479

SHEET TRANSFER MECHANISM Filed Aug. 3, 1948 8 Sheets-Sheet 7 l Ul @www l IN VEN TOR. Hen/v' E. Peyrebrune NOV- 18, 1952 H. PEYREBRUNE SHEET TRANSFER MECHANISM 8 Sheets-Sheet 8 Filed Aug;y 3, 1948 Henri E. Peyrebrune BY M 5W M; M

Patented Nov. 18, 1952 SHEET TRANSFER MECHANISM Henri E. Peyrebrune, River Forest, Ill., assigner to Miehle Printing Press and Manufacturing Company, Chicago, Ill., a corporation of Dela- Ware ApplicationAugust 3, 1948, Serial No. 42,172

The present invention relates to improvements in mechanism whereby sheets of material, such as paper, are fed to a sheet processing machine.

More specifically, the invention pertains to means operative to engage registered sheets and transfer them, one by one, to a moving sheet carrier.

Devices, whereby this principle of sheet feeding is accomplished, have been widely used in-the field of job printing presses and they usually are comprised of either a rotary or an oscillating transfer gripper mechanism, whereby a registered sheet, while at rest, is engaged and then conveyed at an accelerating speed, to a rotating impression cylinder or to any other sheet carrying member of a press.

In such prior art devices the transfer grippers, while conveying the registered sheets to the press, travel merely in a circular path so that the distance or angular travel within which the sheet transfer grippers must be accelerated to the surface speed of the sheet receiving member, is definitely limited. l

In many instances, and particularly so when presses are run at comparatively high speeds, it is difficult to hold register of the sheets, while they are being 'transferred at an accelerating speed to a traveling sheet carrier.

One of the advantages, which my invention provides is an improved motion and mechanism to produce it, whereby the path followed by the transfer grippers is substantially that of a parabola during their travel to and from the stationary support tothe point of transferring th sheets to the 'moving sheet carrier.

In other words, the grippers follow a non-circular path which extends appreciably beyond the location of the point of sheet register, if the grippers were to follow merely a circular path. Therefore, the distance available within which transfer, i. e., to cylinder speed, is correspondingly increased.

This provides for additional inherent advantages. For instance, it permits the locating of the transfer mechanism at a point considerably higher with relation to the moving sheet carrier than has been possible heretofore with known mechanism of this class, thereby, in addition to other advantages, also affording better accessibility to the parts involved for registering the sheets and for transferring them.

Furthermore, the improved mechanism provides for a much smoother transfer of the sheets from the point of register to the sheet receiving 7 Claims. (C1. 271-56) Cil l40 the sheets must be accelerated to the point of 2 member than has been possible with the sheet transfer apparatus known heretofore.

The novel principle involved in my invention also assures a minimum of wear on the parts which constitute the driving mechanism. This is made possible because of the fact that the angular displacement of the driving members, such as gears and other associated elements, is held to a given minimum, while the extent of angular displacement of the sheet transfer grippers is increased very appreciably beyond that of their driving members.

In other words, with a minimum of angular displacement of the driving parts, a very substantial increase in the travel, i. e., angular displacement of the transfer gripper elements is made available.

I furthermore contemplate the introduction of means whereby the sheets, as they approach the front registering guides, shall be retarded by the transfer gripper elements in a manner similar to that disclosed in prior Patent No. 1,991,003 issued to Burt D. Stevens, also assigner to the assignees of the present invention.

With these and other advantages in view, it is one of the primary objects of my invention to provide an improved sheet transfer mechanism of the class specified, in which the gripper elements are caused to travel in a non-circular, such as a parabolic path for the purpose of removing a registered sheet from its support and to thereupon follow a circular path in order to transfer it to the sheet receiving member.

Another object of my invention resides in the provision of means whereby the travel of the sheet transfer grippers shall be extended very appreciably beyond the normal point of register as known heretofore in the art of transferring registered sheets, so that more time will become available for accelerating the sheets to cylinder, i. e., printing speed.

A further object of my invention is to provide improved mechanism whereby the above advantages and objects will be accomplished eifectively and economically.

Still further objects of the invention will become apparent from the appended claims read in the light of the following specification and accompanying drawings in which I have chosen to exemplify the invention as embodied in a printing press.

In these drawings:

Figure 1 is a perspective view showing the general arrangement of the cooperating parts I have provided to effect the transfer of sheet material Figure is a cross section taken in theplane along line V-V of Figure 2 as viewed from` the left;

Figure 6 is a diagrammatic illustrationshowing the path followed by the transfer unit-gripi pers when transferring a sheet from a sheet support to a sheet carrying member, while Figure '1 is a view of cross-section taken on line VII-VII of Figure 3, seen from the right;

Figure 8 depicts a sectional elevation taken along line'V'III-VIIIiof-'FigureZ as viewed from the right and illustrates part of the clutch means forautomatically locking the'fsheet transfer unit to f its :driving means;

Figure-Q is a view similarl tosFigure 8 but' showing the `clutch means `in its tripped or disengaged position;

'Figure 10 is an endzview Vof- Figure 3, and

lFigure 11. is. a diagrammatic view similar to Figure-(ibut showing the pathfollowedy by the transfer grippers when the sheet retardingv principle is incorporated in the device.

Referring now to Figuresl, 2 and 3, the trans- Afer* shaft I0 is shown suitably journalled'for ro- -tation in theiside frames Il' by means of the bearings I2 and I3 andit provides an'oscillating support for a series of transfershaft arms I4 clamped securely theretoand which in turn supportv the gripper shaft I5, which is rotatably mounted'therein.

On: the drive lend of the. transfer yshaft'. Ill-is a drivefdiscl Iwhich'carries the segment I1, said segmentibeingfixed to the drive disc byconventional means suchas' the bolts I8.

.oscillatory motionv is transmitted from the drivedisc I6 to the'transfershaft Il) by'rneans ofi aV clutch consisting. of theV slotted tube I9,

thecompression spring-2ll and the dog or'latch 2I iiXed-tothedepending end of the tube I'which is slidably inserted through an opening. provided therefor inthe transfer.` shaft, and Ycan be raised: or lowered to either engage or disengage the drive discz` I'aswill'be explainedlater.

Thel meansprovided for. imparting` oscillatory motion to the drive vdisc IB andgthereby tothe -transfer shaft I0 is shown in Figure4. YLever 22 is formedwith the segment 23 which meshes with the drive disc segment I1. It is rigidlyV secured on stud 241 by means of the bolt 25 said4 stud `being rotatably. fastened in the'side frame.

Identical rollers 21 and 28 areattached to lever 22 by meansof 4eccentric studs-26 and areopera- Atively. associated with'their respectivevconjugate cams 29-and 3D. The cams in turn are secured to the drive shaft 3| which is timed-to make one -revolution per impression of a two revolution press. By virtue of the contcur'of thevcams 29 and 30,;and the rfollowers 21 and`28, vreciprocating motion is impartedv to the lever 2-2 and thereby tothe drive discv IBby means of 'thesegments I1k and 23. Rollers 21 and 28 are secured` tolever 22 by means of eccentric studs for.` the purpose of providing adjustment whereby thev contact: re-

lation of kthe rollers withtheirrespective cams canbe'maintained and any backlash or play can u .across a-feedboard'l where they are registered i against thefront guides 52.

4 be positively eliminated. They also provide means for varying the extent of travel of the lever 22 in either direction.

Mounted in series on the gripper shaft I5 and in spaced relation with the grippers on the sheet carrying member or impression cylinder, are the ,gripper assemblies 33 having the gripper fingers 34 as shown in Figure 5. Also fixed on the drive end of the gripper shaft bar I5 is the lever 31, secured thereto by means of the bolt 35 and key 36and which carries at its free end the cam follower'38. The latter is secured to lever 31 by means of aneccentric stud 3S which permits adjustmentofr said follower for purposes which will be explained hereinafter. During the transfer operation, follower 38 traverses cam 48 which is rigidly secured to frame II by means of the bolts 4I.

Operating in conjunction with lever 31 and means for imparting relative motion to the gripper pad bar'42 and thereby to the gripper pads 43 mounted thereon, is theflever 44y which is pivotally supported on the end of the gripper shaft I5. Thegripper pad bar'42is in turn rockably supported by brackets `mounted on the gripper-shaft I5 and which are inserted'in the depending ends of the arms I4, see Figure '1. Attached to the free end of lever 44- and also by eccentric means'is` the cam followerSSA which is identical to roller- 38 on lever `31. During the ltransfer movement roller 38A rides'on fixed cam 45 which is also fastened to-the frame I I.

Pivotally attached to lever 31`by means of the stud 45 is the rod 41 having its free endslidably insertedthrough the projection 48 of lever 44. A compression springll, concentrically mounted on rod 41, exerts pressurebetwe'en the projectionfi'of leverv 44and the end of rod 41which is attached to lever 31, urging said lever `in a counter-'clockwise direction thereby imparting like motion to thegripper shaft I5 and the grippers-33, maintaining the gripper fingers 34 in contact with their associated pads 43. In order tc'regulate the extent of counter-clockwise movement'of lever 31vand consequently the amount of pressure between'the gripper fingers and their associated-pads, the-set screw 5 is adjustably threaded in lever i4-with its end contactingthe stud 46 in lever 31.

In mechanisms 'of thistype the sheetsto be transferred are fed lin any conventional vmanner To permit transfer of the sheet after it has' vbeen registered, the front guides are-receded by means of the lever 53 pivoted at 54and having attached to its free end cam follower 55 which rides on the revolvingv cam Y 56 mounted on shaft 3l.

Means for opening-andclosing the grippers'33 to engageeach succeedingfsheet is provided' in the cam 51 which issecured to lever 58, said lever being rcckablymounted von stud 59 and having attached to its free end cam follower 6U which rides on the revolving cam 6I also mounted on shaft'3l. MovementA of cam'l raises and lowers lever. Et'thereby moving camv 51 into and outof thepath of cam-follower'v 3B; of'lever 31 atthe proper-time to open'and close'the grippersA 331as they move to take a sheet to be transferred. Thespring androd assembly 62 maintains the cam' follower 662 inxintimate relation witnthe cam 6I.

During thev transfer of a sheet the grippe fingers` 34 andv pads-43 follow a substantially parabolic path as shown. in FigureV 6,i with the `sion cylinder B at the point of transfer.

grippers and pads moving tangent to the impres- The circular path followed by the grippers in conventional sheet transfer mechanisms is shown by the broken line C in Figure 6, also in Figure 11, thereby indicating the extent of change in the path followed by the transfer grippers, which improvement has been made possible by the development of my invention. By following the parabolic path, the distance travelled by the grippers between the front guides 52 and the point where the sheets are transferred to the cylinder B is substantially increased, allowing more time to gradually accelerate a sheet from its register position against the front guides to the surface speed of the cylinder at the transfer point, thereby eliminating any abrupt pull on the sheet which might otherwise disturb its register.

At the point of transfer the cylinder grippers D close on the sheet while the transfer grippers begin to open due to the movement of lever 31 as the cam follower 38 traverses the high point of cam 40. This movement of lever S1 in a clockwise direction against the pressure of spring 49 also turns the gripper bar I5, thereby moving the gripper fingers 34 away from the pads 43 in order to release the sheet to the cylinder grippers D. After the sheet is released by the transfer grip,- pers they are again decelerated to a stop before their return for the next sheet. On their return stroke the transfer grippers pass tangent to the impression cylinder B after it has completed its rst revolution and preferably when the recessed portion or gap G of the cylinder presents itself at that point.

Referring now to Figures 5 and 7, it will be seen that pivoted at the opposite end of the gripper shaft I5, and operating in conjunction with lever 44, is the lever 63 as shown in Figure '1. Supported at one end of lever 63 is the gripper pad bar 42, while to its free end is attached by eccentric means the cam follower 38B which is identical to those on levers 31 and 44. Cam follower 38B rides on cam 54 which has the same contour as cam 45 in Figure 5.

Due to the contour of the cam 45, see Figure 5, the lever 44 is caused to pivot in a clockwise direction about the axis of the gripper shaft I5 as the complete assembly rocks counter-clockwise about the axis of the supporting shaft I0, whereas the direction of rotation of the lever 63, as viewed in Figure 7, because of the contour of the cam B4, will be in the counter-clockwise direction. This compound movement causes the gripper pads 43 and their associated gripper fingers 34 to follow a parabolic path thereby effecting a displacement of said ngers and pads beyond that in which they would normally travel if moved in a circular path with the same relative angular displacement of the transfer shaft I0.

The three followers 38, 38A, see Figure 2, and 38B, see Figure 7, are afxed to their respective levers 31, 44 and 63 by eccentric means to make possible adjustments in order to eliminate any play or lost motion that might develop in the mechanism, also to prevent any torque or twist in the gripper pad bar 42 which extends the full width of the mechanism and would otherwise be subject to considerable torsional strain.

To maintain the cam followers 38A and 38B of levers 44 and 53 respectively in contact with their associated cams 45 and 64, a spring and rod assembly as shown in Figure 7 is used. One such assembly being installed in the transfer shaft arms I4 at each end of the transfer shaft as shown in Figures 2 and 3. Rigidly secured to the gripper pad bar 42 is the bracket 65 to which is pivotally attached the rod 66, the free end of which is slidably inserted through the pin 61, said pin being rotatably mounted in the transfer shaft arms I4. The compression spring 68 exerts pressure between the pin 61 and the rod B6 urging the levers 44 and 63 in a counter-clockwise direction and thus maintaining the followers 38A and 38B in contact with cams 45 and 64.

In the event a sheet is not registered properly at the front guides the transfer shaft clutch is disengaged by the tripping mechanism shown in Figure 8. This mechanism can be actuated by any conventional sheet detector and as the detector is not a part of the invention, it is not shown.

When a sheet is fed in proper register the lever 69 pivoted on shaft 15J is depressed by a sheet detector to the position shown with its end 1| in the path of the plate or stop 12 on lever 13 which is clamped on shaft 14 thus preventing cam follower 15 from remaining in contact with the revolving cam i8 mounted on shaft 3|, Also clamped on shaft I4 is the lever 11 having projection 18 and to which is pivotally attached the rod 19. The free end of rod 19 is slidably inserted through the boss 8B. Concentrically mounted on rod 19 is the compression spring 8|, the pressure of which tends to move the lever 11 and thereby the lever 13 in a counter-clockwise direction maintaining cam follower 15 in contact with cam 16 or the stop 12 in contact with end 1I of lever 69 depending on whether or not the press is tripped.

If however, a sheet arrives out of register, the sheet detector will not depress lever 69 so the end 1| will not interrupt stop 12 and cam follower 15 urged by the spring BI will remain in contact with cam 18, which action permits lever 11 to rise causing its projection 18 to move into the path of and press on plate 82, compressing the spring 2|) and moving latch 2| and tube I9 to the position shown in Figure 9.

In this position the latch 2| is raised out of the V-shaped slot 83 in the drive disc I6 and rides on the surface 84 within the disc. In the same action the tube I9 is raised bringing the slot 85 in line with the drive edge of the disc I allowing the disc to oscillate without contacting the clutch tube I9.

As long as a properly registered sheet is not present at the front guides, the tripping mechanism will maintain the clutch in its disengaged position by raising and holding the latch 2| in its depressed position each time the opening 83 in the disc reaches the point of engagement. However, as soon as a sheet is delivered at the guides in correct register the tripping mechanism will cease operating and the latch 2|, forced by pressure of the spring 20, will drop into the slot 83 in the drive disc when it reaches the proper position and the transfer mechanism will again oscillate with the drive disc I6.

To prevent the transfer unit from being disengaged in any but two predetermined positions, the safety disc 86 is provided. The safety disc has two openings 31 and 88 into which the tube I9 must enter in order to disengage the clutch. In any intermediate positions the tube I9 is maintained in its engaged position by the inner surface 89 of the safety disc.

The automatic tripping mechanism will only disengage the clutch in the position shown in Vtoa position' in line with tube `I9.

Figure. The other'position is usedyfor manually tripping; the mechanism" in an extreme position wherein' the impression cylinder and the transfer mechanism aremore accessible for. adjustments or make-ready.

Manual-tripping of the transfer mechanism is controlled'by'the' locking pin=90 andhousing 9! shown iniFigure 10, which, a's illustrated', .can be turned to'two positions indicatedon the.- surface plate 92 as Run andvLock.

The mechanism' involved when' tripping'the device manually can'A be seen more' clearly in Figures 2 and'S-wherein the pin90 .is shown a'sbeing set in the Run position indicated in Figure 10. To trip the mechanism, pin `90 is pulledout against the pressure of the spring y93 acting against flange 94 until the end 95vis1withdrawn from its seat in the plate 92. Pin.A and thereby housing 9|, which is fastened to shaft 9`Slby means of the key 91, are then turnedin a counter-clockwise direction until they reach the Lock positionat which time end-95vof pin 9'0will drop into a seat provided to hold itin said position. -Any movement of the housing and pin will of course impart a like motion to'the Vshaft 96 which is mounted concentrically in the transfer shaft I0, and suitably journalledtherein atv each end. On the drive end of the shaft 96 is the-eccentric projection 98 which projects into ltheslot 99 in tube I9 of the clutch mechanism.

Therefore', as the shaft 95 is turned the'eccen- 'tric98 contacts the upperY edgeof the'slot 99 in tube I9 tending to raise the tube against the pressure of the spring 20. However, the tube I9'will-remain in the position shown in Figure 2 by virtue of the safety disc 86 until the transfer mechanism reaches a position in which the tube I9 is'in line with one of the'two openings 81'01' 80l in the'safety disc. At either point the tube will be raiseduntil it projectsinto oneY of Vsaid openings which'will bring the latch 2l out of the V-shaped slot 83 in the drive-disc I9 and will move the slot185 in line with the drive edge of said disc. As long as the pin 90 remains'in the Lock position-eccentric 93 willmaintain the `tube I9 .in its raisedv or disengaged position and vthe drive disc willlcontinue tooscillate .without affecting the transfer mechanism.

To re-engagetheclutch, pinlllv and the-parts connected thereto, are turnedto the Run position which moves the eccentric to its lowered position as shown and wherein it-will cease'to maintain .the tube I9in its raised position. Howeveigthe tube rI9 will'remain inits disengagedposition with the latch riding-on the-innersurface'- 84iof the drive disc I Suntil the Vshapedrslot83 moves Then, due to thepressure of spring2-0-theztube and latch k,will againv spring into engagement'. with' ,the` disc I6 andthe :transfer .mechanism 'awill again. op-

erate,

Precision timing.: of' the impression cylinder .grippers for opening, and closing; on 'the' transferred sheet is. essential/and is accomplished by meansfof. the loam-|00 attachedrthereto.- The raising andlowering of the lever 58 by v-irtuesof the cam BI causes cam I tom'oveinto and out ofthe path'.of-theimpression cylindery gripper opening lever to effect -theopening andV closing press; lquirements of themost rapid automatic sheet '8 of the impression cylindergrippersiin timed relation-tothe .transfer grippers.

Likewise, the impressiony cylinder lgrippers;- are vopened'to release a printedsheetA to thedelivery .mechanismnot shown, by. means which'are also actuated by lever'58. Pivotally attachedrtdthe -freeend IOIL of lever'is thearcuate segment `|02 which is rockablyfmount'ed on theframe'by meansof' the stud |03. In mesh withv thesegment |02 isfanother segmenti |04' having' eccentrically 1 attached thereto.' by means. of studV I 05 l thebar or.- shaft Illl which in .turn` is pivotallyf connected tothe impression cylinder gripper opening cam Said cam being rockablymountedon the framev I'I by means-of the stud |08. It can be -seen'that any lowering or lraising of lever 58 will `impart a `relativemotion'to the cam IOTby-virtue of the segments I02and.|04 and the shaft'IU/ which will bring said cam into and out-of the path of -the lcylinder gripper opening' lever in fed presses and stream feeders, litV can also-be used with equal efficiency on hand fed-presses or pressesI equipped'withysheet by sheet feeders. As is lwell known in theart, however, the-'greatest difiiculty encounteredwith sheet 'by sheet feeders, whenan attempt is madetoincrease the` speed, is the-rebounding of the sheets from the'front register guides, or in cases where'thin sheets such as onion skin arefused, the leading edge is apt to curl backV when it' strikes the'front guides. To prevent such difficulties it often becomes necessary to reduce the speed of the feeders and consequently the speed of the pressyresulting in a corresponding'loss in production.

'If desired and as indicated'herein, the'device could readily be modified to permit additional retardation ofthe oncoming sheets, just before they contact the front' guides. Thereby any possible rebounding or'curling back of' the sheets atthemoment whenthey contact the 'front'guides V52 would be prevented. Insome cases;this'meth od may be'preferred.

,For this purpose, andias shown inFigure `1,1, the contourof vcam 51 is altered to provide'for'the extended travel of the grippers pastthe point at lwhich a registered sheetis grasped. The addition of slowdown ngers |09 provides means for retarding the speedof the oncoming sheet as it isfed over the sheet support 5I to the 'front guides 52. Said fngersintercept the-sheet while they are moving in the same direction and at slightly less thanthe speed'of thevsheetand-then ,they decelerate gradually untilv movementl of the. sheetis practically nil` when it reaches vthe front guides 52. During this slowdown procedure vthe leading edge ofthe sheetlisprevent'ed .fromvcurling back on the slowdown fingers by the lower face ofthe gripper pads 43`whichalso hold the sl'eetsin position at thefrontpguides'until the gripper fingers. 34' close" on the lea'dingedge. The gripper fingers' remain' open'during the slow- .down procedure" a'n'ddo notcloseon'the sheet until ity has been registered against the front guides 5.2.`

'The'. operation of' the mechanism 'for trans- Aferrin'gthe registered sheets' is'v as follows:

A sheet 'to be transferredis` at rest on the sheet support after having been registered by the front guides 52 and the gripper fingers 34 have closed on the leading edge as shown in Figure 5. Rotation of the drive cams 29 and 3i) shown in Figure 4 will impart an oscillatory motion to the lever 22 which in turn will transmit a like motion to the drive disc it and thereby to the transfer shaft l. When the transfer mechanism starts its clockwise movement the front guides 52, see Figure 5, are simultaneously withdrawn from the path of the sheet, actuated by the lever 53 as the cam follower 55 rides over the high part of cam 56. The cam follower 38A of lever M then rides on cam 45 with the spring 49 maintaining lever 3'! in the position shown with the gripper ngers 34 closed on their associated pads 43. The two levers 3'! and 44 travel as a unit, starting in a linear path substantially parallel to the sheet support 5| and then following a substantially parabolic path, see Figures 5 and 6, until they reach the point at which the sheet is to be transferred to the impresison cylinder. Then cam follower 3B of lever 3l contacts the raised portion of cam 40 which causes lever 31 to compress spring i9 and turn the gripper shaft l5 in a clockwise direction thus opening the gripper fingers 34.

While this action has been taking place the lever 58 was lowered by virtue of the cam 6|, moving cam 51 from the path of the cam follower 38 and placing cam it@ in the path of impression cylinder gripper operating lever. When the impression cylinder grippers arrive at the transfer point they are open to engage the sheet and close on it an instant before the transfer grippers release their hold. The transfer grippers continue to rotate in their clockwise direction as viewed in Figure 6 until they are clear of the sheet, thereafter they reverse their direction and return for engaging the succeeding sheet` On the return stroke the transfer grippers pass the impression cylinder while the recessed portion or gap G thereof presents itself.

With the return of the transfer grippers, lever 58 begins to raise also as cam follower @il rides on the low portion of cam El bringing the cam 5l into the path of cam follower 35. When the follower 38 contacts cam 5l, see Figure 5, the lever 31 will again compress the spring le there` by turning shaft I5 in a clockwise direction and opening the gripper fingers 34 as they return to receive the next sheet. Cam 5l holds the lever 37 in this position with the grippers 31% open until they are in position to close on the succeeding sheet. By this time lever 5t has begun its downward movement carrying the earn 5l away from the cam follower 33 and allowing the pressure of spring i5 to close the gripper fingers 3!! on the pads d3 clamping the edge of the sheet therebetween.

While I have herein disclosed a preferred embodiment of my invention and merely by way of example, it shall be understood that I do not wish to be limited to the precise details illustrated and described, because many modications in structure and mode of operation may be introduced without departing from the principle of my invention and scope of the appended claims.

I claim:

l. In a sheet fed printing press, the combina tion of sheet registering means, a sheet carrying impression cylinder provided with sheet engaging grippers, an oscillating transfer gripper mechanism including sheet engaging elements for grasping registered sheets and transferring them to the grippers of said cylinder, driving means for oscillating said transfer gripper mechanism, and an oscillating cam member associated with said driving means for opening and closing the sheet engaging elements on the transfer mechanism, as well as for opening and closing the grippers on said cylinder.

2. In an oscillating sheet transfer mechanism for transferring sheets from a position of rest on a feed table to a continually rotating impression cylinder of a printing press or the like, the combination of gripper elements, drive mechanism for oscillating said elements, means associated with said drive mechanism including cam members arranged to guide said elements during their transfer motion in a manner that the initial portion of their movement is in a path substantially parallel to the feed table and thereafter, in an arcuate path tangent to the impression cylinder, and means associated with said drive mechanism for rendering the transfer mechanism inoperative when a sheet is misfed.

3. A sheet transfer mechanism as set forth in claim 2, wherein selectively automatic and manual means are provided for rendering the transfer mechanism inoperative.

4. In an oscillating sheet transfer mechanism for transferring sheets from a position of rest on a feed table to the grippers of a continually rotating impression cylinder, the combination of gripper elements, drive means for oscillating said elements, means including cam members arranged to guide said elements in a substantially straight path parallel to the plane of the feed table during the initial portion of their movement and thereafter in a circular path tangent to the impression cylinder at the point of transfer, and oscillating alternately effective cam means associated with said drive means for controlling the opening and closing action of the impression cylinder grippers at the moment when a sheet is being transferred to said cylinder, as well as when the sheet is to be released in order to deliver it.

5. In an oscillating sheet transfer device for feeding sheets from a position of rest on a feed table to a continually rotating impression cylinder, the combination of gripper elements, a supporting shaft for said elements, a disc rotatably mounted on said shaft, drive mechanism for oscillating said disc including conjugate cams, and clutch mechanism associated with said disc and operative to transmit motion from said disc to said shaft, selectively manual and automatic means for disengaging said clutch in a plurality of positions, and safety means operative to prevent disengagement of said clutch in any but a predetermined position.

6. In an oscillating sheet transfer device for feeding sheets from a position of rest on a feed table to a continually rotating impression cylinder, the combina-tion of sheet gripper elements, drive means including conjugate cams for oscillating said elements, stationary cam means arranged to guide the gripper elements in a straight path parallel to the plane of the feed table during the initial portion of their transfer movement and thereafter in a circular path tangent to the impression cylinder in order to transfer a sheet thereto, additional cam members for opening said gripper elements at the point of transfer, and oscillating cam means associated with said transfer mechanism t0 control the cylinder gripper action when taking a sheet from the lil transfer mechanism. as Well as whemreleasing it f or delivery.

v7. 'Ina sheet `feeder .for transferring sheets from a feed table-to a icontinuallyrotating sheet carrier, the' combination 'comprising transfer gripper elements, Aa `gripper shaft; means for oscillating'said gripper elements includingasta'- tionary cam and a lever-rotatably mountedon thegripper shaft for controlling the movement ofthe gripper elements in a' manner that the initial -portion of their' transfer motion-is in'fa substantially `sl',rai,=,fht path parallel tothe plane oftthefeed table andthereafter ina circular-path tangent to theV sheet Vcarrier.l inv order to transfer a `sheetthereto, a second leve1--iixedon said grippershaft, camfmeans arranged to-cooperate with said second lever for'the purpose-ofopening thegrippers at thezpoint of transfer,A resilient 12 means-:constantly urgingz'saids levers into:` relative predetermined positions;randfmeanszprovidedon said'rst mentionedl lever forsadjusting `the re1ative-positions Voir said levers.

HENRI E.v PEYREBRUNE.

yREFERENCES CITED Thefllowingreferences.are of record`in the le ofv this .-patent:

UNITED. STATES 'PATENTS Number Name Date 2,092,189. Stebb .Y Sept. 7, 1937 2,128,317- `Peyrebrune lAug'..30, 1938 2,221,500 Upham Nov. 12, 1940 2,422,996` Wendt ,June'24, 17947 2,424,732 .Bellucheet al. v rJun/29, 1947 

